If you mean the boot up screen that is supposed to be from the ram chips IIRC

I think only the original type will produce the nice blocks of B&W. Other chips produce vertical lines or horizontal pattern. Don't read too much into the initial boot screen. I've got numerous Orics that produce numerous patterns. and yet they all boot up OK.

Do the checks and try changing that reset capacitor. Check the timers.

About the smaller ICs 8, 21,... , anything interfacing with the memory may cause the computer to hang if if fails, but I've never heard of an Oric with such failure alone. The 6522 and the ULA also may cause this. The ULA has a good probability of being ok as you have an image, but who knows... The 6522... I wonder if you could somehow disable it. Maybe setting the CS pin, accessible in the expansion bus as IOCONTROL, to low, or by unconecting the Vcc pin. The Oric should boot, almost. At least to point where IRQs are expected.

I doubt the sound chip may be the cause, as it is interfaced through the VIA and used for sound, of course, and reading the keyboard.

My RAM chips don't feel warm. As these chips tend to want replacing and you seem to have spares it might be worth removing them and fitting sockets and putting a fresh set in.
Did you go through the test procedure here? http://oric.signal11.org.uk/html/repairguide.htm

If the 6502 and 6522 are OK and the RAM have been changed (!) then there is the 74ls04 and 74ls257 that can sometimes throw up some odd errors, but to me it looks like one of the main chips that is at fault. Check for broken tracks .

Again, if you could use the LA on the address bus signals during boot (just a few cycles) it could give us more hints... if not those, the data bus signals. I could calculate the values that should appear, if you are interested.

About the RAM chips, you see that people who repair these old computers usually desolder all of them, put sockets and substitute chips as a first step. It seems to be a common problem. I wouldn't dare to do anything similar.... I am too dumb and dangerous using a soldering iron

Why don't you check continuity of the address and data lines between the 6502 and the memories? That should be easy to do and may be worth checking...

Thanks for your help, but i'll don't try more. It only makes me angry. Angry as hell. The Oric 1 works, so who cares ... i don't have a cumulus (seems to be sold out and i sent godzil 2 pms without an answer .. strange, 'cause i asked in a very polite way - but some gods are not willing to give an answer to the ordinary people) or other newer mass storage solutions, so it is completely senseless and there is no reason to sell my soul for this.

Okay. Sorry for not being more helpful. The best idea, then, is converting your 1 in an Atmos, by putting the 1.1 rom, changing or adapting the keyboard connector, and using the Atmos case. The other would be good for replacements.

About mass storage solutions, I would not expect a new cumulus anytime soon. Godzil is usually very active and responsive, but I guess he is quite busy now.

Best option is Silicebit controller, but he is also too busy now, so doesn't come here often. I heard he had some trouble with components imported from China not arriving or having delays of months. But I am sure he will mount the controllers as soon as he can.

Just keep connected to this forum to exchange experiences and keeping up to date with new productions!